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                                                           OMB APPROVAL
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                                                  OMB Number           3235-0287
                                                  Expires:        April 30, 1997
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                     U.S. SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                     FORM 4

                  STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

    Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934,
       Section 17(a) of the Public Utility Holding Company Act of 1935 or
               Section 30(f) of the Investment Company Act of 1940

[  ] Check this box if no longer subject of Section 16. Form 4 or Form 5
     obligations may continue. See Instruction 1(b).

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1. Name and Address of Reporting Person

Tombros,                Peter     G.
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   (Last)               (First)                 (Middle)

159 Lambert Road
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                                    (Street)

New Canaan,               CT                     06840
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   (City)               (State)                 (Zip)


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2. Issuer Name and Ticker or Trading Symbol


Enzon, Inc. (ENZN)
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3. IRS or Social Security Number of Reporting Person (Voluntary)


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4. Statement for Month/Year

May 1997
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5. If Amendment, Date of Original (Month/Year)


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6. Relationship of Reporting Person to Issuer
   (Check all applicable)

   [ X ]   Director                             [   ]   10% Owner
   [ X ]   Officer (give title below)           [   ]   Other (specify below)


          President and Chief Executive Officer
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           Table I -- Non-Derivative Securities Acquired, Disposed of,
                             or Beneficially Owned
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6. 4. 5. Owner- Securities Acquired (A) or Amount of ship 3. Disposed of (D) Securities Form: 7. Transaction (Instr. 3, 4 and 5) Beneficially Direct Nature of 2. Code ------------------------------- Owned at End (D) or Indirect 1. Transaction (Instr. 8) (A) of Month Indirect Beneficial Title of Security Date ------------ Amount or Price (Instr. 3 (I) Ownership (Instr. 3) (mm/dd/yy) Code V (D) and 4) (Instr.4) (Instr. 4) - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ ====================================================================================================================================
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly FORM 4 (continued) Table II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities) ================================================================================
9. 10. Number Owner- of ship 2. Deriv- of Conver- 5. 7. ative Deriv- 11. sion Number of Title and Amount Secur- ative Nature of Derivative 6. of Underlying 8. ities Secur- of Exer- 4. Securities Date Securities Price Bene- ity: In- cise 3. Trans- Acquired (A) Exercisable and (Instr. 3 and 4) of ficially Direct direct Price Trans- action or Disposed Expiration Date ---------------- Deriv- Owned (D) or Bene- 1. of action Code of(D) (Month/Day/Year) Amount ative at End In- ficial Title of Deriv- Date (Instr. (Instr. 3, ---------------- or Secur- of direct Owner- Derivative ative (Month/ 8) 4 and 5) Date Expira- Number ity Month (I) ship Security Secur- Day/ ------ ------------ Exer- tion of (Instr. (Instr. (Instr. (Instr. (Instr. 3) ity Year) Code V (A) (D) cisable Date Title Shares 5) 4) 4) 4) - ------------------------------------------------------------------------------------------------------------------------------------ Stock Option Common (right to buy)(1) $2.688 4/15/97 A V 300,000 (2) (3) Stock 300,000 300,000 D - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ ====================================================================================================================================
Explanation of Responses: (1) Option grant pursuant to the Company's Non-Qualified Stock Option Plan and exempt under Rule 16b-3. (2) The option vests and becomes exercisable on April 5, 2002; provided, however, that the option will immediately vest and become exercisable as to (i) 100,000 shares should the closing price of the Company's Common Stock as quoted on NASDAQ be at least $4.00 for twenty consecutive days; (ii) 100,000 shares should the closing price of the Company's Common Stock as quoted on NASDAQ be at least $5.00 for twenty consecutive days; and (iii) 100,000 shares should the closing price of the Company's Common Stock as quoted on NASDAQ be at least $6.00 per share for twenty consecutive days. (3) The options expire five years from the date of vesting. /S/PETER G. TOMBROS 6/10/97 - --------------------------------------------- ----------------------- **Signature of Reporting Person Date ** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a). Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedures.